I haven't seen pirated PDF copies of the E46 Bentley online. Buying the electronic version costs just as much as the print version.
I would recommend that you just buy the manual. It will cost about $100, I know, but give the cost of labor on these cars, it will pay for itself.
I, too, was a student when I bought my first BMW, and the Bentley was the best purchase I could have made for my car.
Any project you have pending, you can just come and ask for help. There is a lot of knowledge here.
I am sorry I couldn't be more help.